Work holder chuck device



June 28, 1960 w. A. zALE WORK HOLDER cHucK DEVICE 2 Sheets-Shea?I 1 Filed March 5, 1959 n m m 2 www@ A z Ae l i mA Z w June 2s; 1960 w. A. ZALE 2,942,891

woRK HOLDER CHUCK DEVICE Filed March 5, .1959 2 Sheets-Sheet 2 INVENroR WHATS/6 ZALE ATTORNEY nited States Patent WORK HOLDER CHUCK DEVICE Walter A. Zale, Flint, lVlich., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Mar. s, 1959, ser. No. 797,473

1o claims. (ci. 279-1) This invention relates to work holder chuck devices and more particularly to precision chuck holding devices for positioning an object that is to have an inside diameter machined concentn'cally with respect to its outside diameter.

Commercial outside diameter work holding devices presently available, such as three-jaw chucks and precision collets, provide only for limited degrees of concentricity between respective inside and outside diameters of particular work pieces. These devices can only guarantec maximum eccentricity to approximately .001 inch. Such a limitation is believed to result from the employment of moving mechanical members in the currently used Work holders. Many present manufacturing processes require errors of concentricity to be less than .001 inch and will continue to require more precise tolerances as our machine age becomes more complex. Therefore, the value of the present invention is readily apparent.

Accordingly, among the objects of this invention are the provisions of a work holder chuck device for accurately positioning and holding an object by its outside diameter -to permit concentric machining of an inside diameter, and provisions for reducing errors in concentricity to a minimum by eliminating moving mechanical parts in a work holder chuck assembly.

The aforementioned objects are accomplished by expanding and contracting a cylindrical work holder about the work piece to allow insertion, machining and removal operations. The work holder member incorporates .a hollow cylinder of temperature responsive material such that the inner diameter `of the cylinder is uniformly expanded to receive the work piece therein and is uniformly contracted by a cooling uid or other means to rigidly hold the work piece during a machining operation.

In the drawings:

Fig. 1 is a cross-sectional'view of one embodiment of the present invention showing the individual parts assembled to form a work holder chuck device;

Fig. 2 is an end view of Fig. 1 more clearly illustrating the shape and disposition of parts comprising the subject invention;

Fig. 3 is a cross-sectional view of a preferred embodiment of the temperature responsive cylinder closure member incorporated in the present invention; and

Fig. 4 is an end view of Fig. 3.

Referring now to Fig. 1 of the drawings, a work holder chuck device embodying the subject invention incorporates a base member containing a iluid inlet passage 12 and a iluid outlet passage 14 to direct uid to and away from an integral temperature responsive work holder cylinder 16. The temperature responsive work holder cylinder 16 is provided with a work receiving recess 18 having an inside diameter of Aa predetermined size. A work piece generally indicated at 20 is shown as positioned in the recess 18. The work holder cylinder 16 is enclosed by a cylinder closure member 22 and forms therewith an annular fluid chamber 24. The temperature responsive work holder cylinder as shown in Fig. l is further provided with a machined shoulder 26 that is engaged by a mating shoulder 28 machined in a face 30 integral with the cylinder closure member 22. The cylinder closure member 22 is secured to the base member 10 by bolts 32 received in aligned holes in the respective members. Conventional fastening means other than the bolts 32 may be employed.

The base member 10 is rigid-ly secured to a machine tool spindle or support generally designated at S. The machine tool spindle or support S contains, for purposes of illustration, a conventional stationary to rotary fluid coupling 34 to transfer fluid to the work holder chuck device. 'Ihe uid coupling 34 includes an inlet passage 36 and an outlet passage 38 each of which extends through the spindle S and by way of a fluid-tight connection 40 yare coupled to the inlet passage 12 and outlet passage 14 in the Work holder base member 10.

Fluid of a regulated temperature and ow is supplied to the stationary to rotary coupling 34 from a heated sup-- ply tank 42 'and a cold supply tank 44. The fluid temperature is selectively controlled by a conventional variable temperature mixing valve 46 while the ilow is regulated by a conventional variable restrictor valve 48. Fluid enters the annular fluid chamber 24 by way of passage 12, ilows yaround the work holder cylinder 16 and through the outlet passage 14 whereby the fluid is discharged to a supply source not shown.

Figures 3 and 4 illustrate a preferred embodiment ofY the temperature responsive cylinder closure member shown in combination with a removable cap member. The cylinder closure member 22 in this conguration comprises a -spiral baille milled recess 50 coacting with the cylinder 16 to provide a helical uid passage 24' about the cylinder. The spiral bathe recess 50 terminates in open ends of cylinder closure member 22', making it necessary to employ a cap member 52 to seal the passage at the Work receiving end of cylinder 16. The cap member 52 has a circular aperture 54 therein that has a diameter slightly greater than the predetermined diameter of the work receiving recess 18 to allow insertion of a Work piece during expansion and retraction of cylinder 16 and at the same time form a liquid seal between the cap and the' cylinder 16. Screws or bolts S6 can be used to fasten the cap and the closure member 22' to the base member 10. This coniiguration assures a more desirable iluid circulation as the spiral recess 50 directs ilow about the temperature responsive Work lholder cylinder 16 while the uid is maintained in continuous contact therewith.

Fluid enters the helical passage 24 in the same manner it does in the previously discussed, embodiment; however, the discharge passages are modied. The cylinder closure member 22 contains a milled channel 58 and a hole 60 that is aligned with a passage 62 in the base member 10. The lluid flows through the helical recess around the work holder cylinder 16 and through the milled channel 58 at the downstream end of the closure member 22. It then passes through the discharge hole I60 to the base pass-age 62 -Whereby it returns to a supply source not shown. p

In operation, the variable temperature mixing valve 46 and the ow regulating valve 48 of a conventional type are provided to cycle ow of a temperature regulated uid to the uid chamber 24 as desired. When the m-achine operator wishes to place a Work piece 20 in the tem perature responsive Work holder cylinder 16, iluid at a temperature approximately Fahrenheit (F.) above room temperature is circulated through-the system to expand the work holder cylinder. A restricting valve can be 'builtin the fluid passage base member 10 or placedA in the external uid lines to regulate the rate of ilow through the 'system to maintain the necessary temperature dierential. Upon expansion of the work holder cylinder the 3 work piece 20 is placed within the holding cylinder 16, and the aforementioned control valve is actuatedY to transmit room temperature fluid through the system to contract Athe cylinder 16. `This contraction of the work holder cylinder causes the cylinder' 'to' rigidly grip the chuck to prevent releasing of the Work object While the where induction heating is used to expand-the chuck, the operator must take measures to determine-whether an excessive amount of heat, due to the machining operation, isV being transferred to the workv holder cylinder.

The components of this work holder c huck are machined to a tolerance of .0001 inch. It has been determined that total movement required for-opening theY chuck is approximately .0004 .inch on the diameter and that an estimated temperature differential of 90 F. will produce this movement. Chuck closing or contracting temperature could be established at approximatelyv room temperature, and therefore the opening temperature would be approximately 90 F. above room temperature. The use'of thisv temperature diiferential would appear to be most advantageous as the room temperature uid is cool enough to contract' the work holder cylinder without additional cooling problems. In the event it is found that an excessive amount of heat is dissipated to the ten.- perature responsive cylinder' 16 to expand the work Vholding cylinder, it is necessary to cool theY cylinder' while the machining operation is in progress. This can be accomplished by. reducingA the huid temperature below that Yof room temperature or Vby'increasing thetrate of ow in the system o both.

The inventionV as described above is directed Vto the use o t a Huid chamber'to convey heat to and away fronr the work holder cylinder 16 to produce the desired expansion and contraction. However, it is obvious that an electrical induction heating unit could be incorporated to accomplish like results. Y

In accordance with the invention, a workl holder chuckA device is. provided to allow precise machiningv of annular objects. The described work holder'chuck does not in-V corporate moving mechanical parts and therefore assures the .reduction in errors of concentricity to the lowest mechanically possible. This reduction in errors Ais attainablesince there are no twisting motions. or distortions normally caused by moving parts.

The above described illustrtionsare obviously subject to modifications without exceeding the scope of. the

appended claims.

` What I claim is: 1

Y' l. A, Awork holder chuck device comprising a base memberadapted to be securedvto a support, van expansible and Acont-ractible temperature responsive member connected v'to said base member, saidtemperature responsive member havingvmcans to receive a Work piece, and means for regulating the temperature offsaid temperatureresponsiemernber whereby said temperature responsivey member contracts'Y to holda workpiece there- Yin and expands' to permit release of said work piece.

idly hold a. work piece therein during a machining op. Yeration and .expands to permit treleaseof said Work piece.

El. Arwork holder .chuck Adevice comprising a base member ,adapted to be securedto a support, a tempera.- tureresponsive lmember secured t said base member Vsize of said inside diameter.Y

4 l and having an aperture therein to receive a work pienn a closure Vmember having a spiral bafiie recess therein terminating in open ends, said closure member being secured to said base member about said temperature responsive member to enclose the same, said spiral baie recess being concentric with said temperature responsive member and forming a spiral iluid chamber thereabout, a cap member connected to the closure member to seal one of said open ends of said spiral chamber remote from said base member, means providing a fluid outlet passage from said one of said ends, said cap membe having an aperture in alignmentwith said aperture in said temperature responsive member to permit theplacing of said work piece within said aperture of said temperature responsive member, and means connected to said device for regulating and transmitting the llow of a variable temperature uid to said spiral chamber through said other open end whereby said temperature responsive member contracts when subjected to prevailing room temperature uid to rigidly hold said work piece therein during a machining operation` and expands when subjected to a relatively high temperature uid to permit removal of said work piece.

4. A work holder chuck device as defined by claim 3 wherein said means providing a uid outlet passage includes a irst passage extending in a substantially axial direction through said closure member and a milled channel in said cap member extending between said spiral iiuid chamber and said first passage. Y

5. A work holder chuck device comprising a base member adapted to be fastened to a support, a temperature responsive work receiving cylinder-connected to said base member, a closure member enclosing said temperature responsive work receiving cylinder, means in said Vclosure memberV defining uid passages between'said closure memberV and said work receiving member, Y and means regulatingfthe temperature and ow of a fluid within said passages to expand andv contract said workreceiving cylinder about a workpiece.

6, A work holder chuck device comprising a base member, a temperature responsive work receiving cylinder integral with the base member and having an inside diameter of a predetermined size, a closure member secured to said base member and enclosing said Vtemperature responsive work receiving cylinder, means in'said closure member defining spiral fluid passages between said closure member and said work receiving member, and regulating means Vfor varying the temperature and owof a fluid within said passages thereby expanding and contracting said Work-receiving cylinder to Lalter the 7. In a work holder chuck device,fa. base member adapted to'be fastened to a support,Y a temperature responsive work receiving cylinderrrc'onnected to said base member, Va closure member enclosing said temperature re'- from said base member, means inV said closure Vmember defining duid passages between said closju'remember, said workVV receiving cylinder and said capV member, and regulating means subjecting said work-receiving cylinde to controhed fluid temperatures and ow thereby expanding and contracting said cylinder about a workpiece.

8. In aV work holder chuck device a source or" high temperature fluid, a source of prevailing room temperature. huid, a temperature regulating valve, a How regulating valve, abase member adapted to be fastened to a SuppOrL'a'temperatui-e responsive work-receiving cylinder connected to said base member, a closure member enclosing said temperature responsive work-receiving cylinder, means in saidclosure defining uid passages b etween said. closure member and saidV work-receiving member-,and means connecting said huid passages, said huid sources, and said valves, thereby subjecting said work-receiving member to regulated uid ows to expand and contract said member about a workpiece.

9. In a work holder chuck device a source of high temperature uid, a source of amibent air temperature uid, a temperature regulating valve, a ow regulating valve, a base member adapted to be fastened to a support, a temperature responsive work-receiving cylinder connected to said base member, a closure member enclosing said temperature responsive Work-receiving cylinder, means in said closure dening uid Vpassages between said closure member and said work-receiving member, and means connecting said fluid passages, said uid sources, and said valves, thereby subjecting said Work-receiving member to regulated fluid oWs to expand and contract said member about a workpiece.

10. In a work holder chuck device a source of heated fluid, a source of ambient temperature ud, temperature regulating means, Elow regulating means, a base member adapted to be fastened to a support, a temperature responsive work-receiving member connected to said base member, a closure member enclosing said Work-receiving member, means in said ciosure defining uid passages between said closure member and said work-receiving member, and means connecting said fluid passages with said uid sources and said regulating means to subject said Work-receiving member to fluid of predetermined temperatures and flows to expand and contract said Workreceiving member about a workpiece.

References Cited in the le of this patent UNITED STATES PATENTS 

